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It appears that many of the rivet holes at the root end of the wings are to be countersunk into the spar caps; a few of those are immediately adjacent to the flanges of the spar caps. What suggestions are there to make those countersink holes. I have quickset countersink tools for precise control of the depth but there is not room for even the small diameter tool.

John Kerr
Xenos B026

John,

Are you talking about the webs of the spar in the way of the microstop countersink? The holes in the spar caps only get countersunk for the skins so that is on the outside (top & bottom) of the spar. I just can't picture any flanges in the way of coutersinking the spars.

Now deburring the holes next to the spar web is a PITA. I used a tiny jeweler's file since I don't have an expensive blind hole deburring tool.

Rick Caldwell
Xenos 0057 67 hrs.

Since I am finishing up my wing now, I just went a took a look. Yeah, there are countersinks on the (upper) spar cap for flush rivets that are close enough to the cap such that my microstop will not fit. I'll need to go back and check my notes, but I assume that I either freehanded the countersink with the cutter or more likely jigged up the spar cap for countersinking with a drill press - sans the microstop mechanism.

I found a used micro stop countersink tool that had been modified. One side of the cage was ground away allowing the tool to be pushed up close. It is a little less stable so I don't use it unless the full cage model wont fit.

I have a modified countersink like Bill. You can also get or make an adapter for the bit and do it by hand, or on a drill press. Just go slow and be careful on the depth.

Thanks for the input. Will continue to explore options.